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Old 27-02-2006, 04:08 PM posted to rec.aquaria.freshwater.plants
Nikki Casali
 
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Default Co2 Day Two: Three fish crash and burn!

ah wrote:

Okay, so I got my CO2 equipment "working," and had it set to release
about 50 - 60 bubbles per minute on a ten hour cycle timed with the
compact fluorescents.

Yesterday went fine. Today, around 6:00 pm (8 hours into the timed
cycle) I noted three fishes were head-first in the plants at the
bottom of the tank and still alive but breathing heavily: a small
dwarf rainbow, and two Madagascar rainbows...

Now, this has to be something to do with the CO2 because I rarely lose
any fish in this tank. So I immediately switched off the CO2 and am
hoping that somehow the fishes will pull through.

I checked the Ph and did not note any substantial changes or a
"crash."


If there has not been a "substantial" pH change then the heavy breathing
is a complete coincidence and not related to the CO2. Then again, what
do you mean by "substantial"? What is your pH now and what was it before?

The pH in my planted tanks is lowered by a value of 0.9. That is from
8.1 to 7.2. This gives a CO2 concentration of about 25-30 ppm. Fish have
no problem with this level. 40 ppm and some fish show some signs of
stress. But I've had 40ppm with no problems whatsoever.

Are these particular fish just sensitive to the extra CO2?
Any ideas on where to go from here? I was thinking I'd start again
with the unit on for an hour or two a day, and gradually increase the
amount of time it is on so that the fish can adapt more gradually.


That will create a short pH swing over an hour and back again. I
wouldn't recommend it. Keep the pH stable. Start with a low constant
bubble count over the 10 hour period, during the light hours. 6 bubbles
per minute over 10 hours is far, far better than 60 per minute over an
hour during a 24 our period.

Nikki